The field of application of the invention pertains to the imaging of a solid, liquid or solid/liquid object, which may be highly multiply scattering with respect to the ultrasonic radiation utilized in the imaging process, and which it may be desirable not to disturb or destroy thereby; such as, for example, a living brain.
As to the prior art, holographic and scanning processes find many applications in medicine and industry, (Journal "IEEE Transactions on Sonics and Ultrasonics," volume SU-15, number 3, pages 144 to 146, year 1972) and (Journal "Journal of the Acoustical Society of America," volume 44, number 5, pages 1324 to 1338, year 1968). As one may see in classical treatments, (Book "Progress in Optics," volume 3, chapter 1, publisher, North-Holland, year 1964) the mentioned processes are not capable of reconstruction of the internal structure of an object when the radiation employed is multiply scattered before it reaches the recording device. At the present time, the application of ultrasonic radiation to the visualization of the living brain (Journal "Journal of the Acoustical Society of America," volume 44, number 5, pages 1339 to 1345) is hindered by undesirable echo-effects and unpredictable or uncalculable obstructions, as for example, the skull bone. If the wavelength is made short enough to resolve small groups of neurons and similar tiny structures, these side-effects become totally unmannageable and, in addition, absorption becomes a major difficulty.